Filter valve construction



Jan. 2, 1962 D. M. SCHWARTZ 3,015,397

Y FILTER VALVE CONSTRUCTION Filed Aug. 22, 1957 3 SheetsSheet 1 INVENTR DANIEL M. SCHWARTZ BY //ML United States Patent O 3,015,397 FILTER VALVE CONSTRUCTION Daniel M. Schwartz, Salt Lake City, Utah, assigner, by mesne assignments, to The Eimco Corporation, Salt Lake City, Utah, a corporation of Delaware Filet! Aug. 22, 1957, Set. No. 679,625 2 Claims. (Cl. 210-395) 'nis invention relates to an improved rotary filter valve for rotary filters such as rotary pan filters, rotary drum filters, rotary dise filters and the like wherein a main filter valve is employed to interconnect, in a predetermined relation, one or more filter sections with a source of reduced pressure.

It is an object of the invention to provide an improved rotary valve wherein the construction and arrangement of the valve mechanism is sturdy and free from delicate parts that ordinarily are the source of much operating difiiculty.

A further object is to provide such a valve that permits a filter to operate more efiiciently and to function With greater accuracy and economy under a Wide range of operating conditions.

A further object is to provide such a valve having large ports, streamlined passages and direct flow o filtrate therethrough whereby greater tonnages of slurry may be dewatered, to a lower moisture content, at extremely low overall costs.

It is a further object to provide an improved rotary filter valve which greatly reduces vacuum losses by reducing turbulent flow, and flow resistant =bends thereby providing smooth unrestricted fioW of filtrate from any of the plural valve ports.

These and other objects and advantages are provided in the improved valve construction for rotary filters which includes rotating port means communicating With a plurality of filter sections of a rotary filtering apparatus, a stationary valve block in operative relation to said port means having opnings therethrongh communicating witlr selected openings in said port means upon rotation et the port means, the openings inaid valve block being shaped to provide a substantially rectinlinear flow path through the openings therein and to selected openings in the port means, and means for maintaining alignment of said valve block with said port means.

The irnproved rotary filter valve of the invention Will be more particularly described With reference to the accompanying drawings showing the valve applied to a rotary pan filter of the type disclose.d in my Patent 2,637,443, filed October 13, 1947 and issued May 5, 1953 and my copending application Serial Number 344,981 now United States Patent 2,811,259 dated October 29, 1957 of which this application is a continuationinpart.

in the drawings:

FIG. 1 is a vertical sectional view of a rotary pan fiiter having connected thereto the improved valve means of the invention;

FIG. 2 is an enlarged detailed sectional.view of a valve and assocated parts of the filter taken at Opposite hand to the view of FIG. 1;

FIG. 3 is a plan view of the main filter block shown on the same scale as FIG. 2;

FIG. 4 is a bottom view of the valve block of FIG. 3;

FIG. 5 is a bott-om view of the main valve wear plate on the same scale as FIG. 2;

FIG. 6 is an enlarged detaed sectional view of a modified form of the present invention;

FIG. 7 is a fragmentary sectional view of the valve shown in FIG. 6 tak en at opposite h-and teretog and FIG. 8 is a fragmentary detailed section of one of the bridge bloeks 152 taken substantially on line 8-8 of FIG. 7.

3,015,397 Patented Jan. 2, 1962 Referring to FIGS. 1 through 5 of the drawings, in which like reference numerals in the several views refer to corresponding parts, the filter illustrated generally in FIG. 1 has a bed 21 which carries brackets 22 mounting a plurality of horizontal rollers 23. The rollers 23 are circularly arranged and support thereon a ring or spider 24 for rotation about the vertical axis of the ring. A plurality of bearing blacks 25 are mounted on the top of the ring, and these in turn support the radially outer ends of filter pans 27, the inner ends of which are carried in bearings 28 mounted on a central column 29. The column, as Will appear more fully hereinafier, is mounted in a. main bearing for rotation about its vertical axis and the ring 24 is united to the column by structural members for rotation therewith.

Tne central column 29 is mounted in a main sleeve bearing 39 supported in the worm gear box or housing 40 carried in turn by the frame member 41. It Will be seen that the spider 24 is connected by integral radial structural arms 42 to the hub 43 which is bolted or otherwise suitably joined to the collar 44 forming a part of the central column 29.

Power for rotating the filter is supplied to worm shatt 48 frein a power source (not shown) and transmitted from the worm 49 to the worm wheel 59 that is bolted or otherwise afiixed to the underside of the collar 44.

The hub 43 is removably secured to the collar 44, as by screws (not shown) and has a depending cylindrical skirt portion 43 that projects into the circular opening provided by the annular fiange 40 of the gear housing 40 and slidingl engages a packing included between the retainer ring 4G, secured to.the top of the housing, and the annular flange 40', thus.insuring that the interior of the gear housing is properiy sealed. l-t Will be noted that the diameter of the opening 40 in the gear housing is slightly greater than the diameter of the worm wheel 50 so that the latter may be conveniently inserted into and removed from the housing.

Central column 29 bas a plurality of longitudinal con duits 51., one corresponding to each filter pan, and through these conduits connection is made between the filter pans and the main valve assembly, generally designated 52.

As best seen in FIG. 2, the central column is provided -at the bottom with a combined wear plate and valve black support 53 that is secured to the column by screws 54. As shown in bottom view in FIG. 5, the plate 53 bas a pluralitv of holes or column ports 55 that register Witir the conduits 51 in the column when the plate is bolted in place and provide substantially rectilinear flow for gases, liquid and the like passing through the ports 55 into the conduits 51.

A valve shaft 58 is secured in bore 56 in the plate 53 by means of a key (not shown) inserted in. the socket 59 and engaging the keyvvay 57.

Valve block 60 bas a central cylindrical chamber6l into which the valve shaft 58 depends. The top opening of the chamber is fitted with a bushing 62 in which the shaft 58 rotates. A combination bushing and Spring retainer 63 is -fastened to the bottom of the valve shaft and rotates in the chamber 61 engaging the interior walls thereof. Compressed between the bushing 62 and the spring retainer 63 is a spring 64 which presses the bushing 62 and the valve block into tight sliding engagement With the wear plate 53. The bottom opening of the chamber 61 is closed by a pipe plug 65.- v

A dust boot 66 is fastened between the worm gear hous- -ing 40 and the valve block 60 ly rings 60 and 6O.

The valve block is prevented from rotating With the central column 29 by connectingit through an adjust able connecon to the worm gear housing 4l). Sueh conports are in the open position.

hectidn includes the ann 67, and the angle arm 68, and

the braclet 69. A nut 70 retains the angle arrn 68 in position in the bracket 69, and by adjusting the position of the nut on the arm, it will be seen that the angular relationship of the valve block to the gear housing may be varied within certain limits. A

The valve block is provided with suCtion passages 71 which eXterid in a stright path through the block and register with the openings Or ports 55 in plate 53 as the valve 'iS rotatecl again permitting unrestricted rtilinear flow through the valve into the conduits 51 When the A suction pipe 72 is Bolted to the bottom of the block. As will -be understood, the suction pipe connects With a conventional evacuator (mot shown).

inner trunnion 75, borne in bearing 28 on the center column, and a radial outer tiunni0n 76, journalled in bearing carried by the outer ring of the spider 24. The enter trunnion 76 has an end portion to which is attached a reversing lever 78.

The inner end of trunnion 75 is provided with a wear plate 79 rigidly fastened to the trunnion, and a spring 80is compressed between the wear plate 79 and a bushing 81 in the bearing 28. The spring 80 forces the wear plate 79 and the filter pan into sealing engagement With a valve seat 82 carried by the center column. The periphery of the wear plate has clearance Within the lsearing 28. A sealing ring 81 is received within the outer end of the bearing 28 and engages the trunnion 75 to retain lubricant within the bearing.

Each of the filter pans 27 has an identical filter cell on its top and bottom. The upstanding sides 83 of the cell provide a receiver for a charge of slurry to be filtered. The bottoin ofthe charge receiver is formed of a filter medium consisting of a rig-id Wire screen 84 overlayed by a piece of filtercloth 85.

EaCh 'filter cell has an inner chamber 89 connected by a conduit 90 extending through the inner trunnion to a port 91 leading to one of the vertical conduits 51 in the center column.

An automatic device is provided for rotating each pan one half of a revolution on its trunnions for each revolution of the center column and spider as more fully set forth inmy Patent No. 2,637,443.

In operation rotation of the filtr is in a clockwise direction. The cycle of operation will be described for a single pan, it being understood that succeeding pans will follow the same cycle with a sixty degree lag.

The cycle will 'be assumed to start after the suction phase*has been completed and the column port of the main valve begins to overlap the blow port 73. The column port and blow Port are of such'size and so positioned 'With relation to each other that blowing continues through a 45 rotation et the filter. For the first 5 of the blowing phase, the panTemains horizontal and the cake is raised fiom the filter cloth and loosened preparatory todumping. After the 5, the turmng lever 78 and camg93 begin to cooperate to invert the pan and such operation continues through an arc et 40; at this point the pari is completely inverted and the c ak has been dumped. Blowing pressure is maintained on the upper or cake-containing cell from the 0 positionto the After the first 45 et filter rotation thecolumn port passes"the blow port, and, during the next 60 cf travel,- the column.port is blafiked off by a portion of the solid areaof the main valve block as-seen in FIG. 3. In this sector, the pan passes under a sluiceway and the upper cell is filled. The blanking ol dring filling prevents applying suction to the pan until it is Conipletely filled so that air is not drawn through the filter medium redncing suction to the other pans; With materials that are -fairly fiuid, flowing out freely to coVer the bottOm of the pan, the blank section may be reduced.

Beginning at the column port registers With the suction passages 71 in the valve block and suction is applied to the upper cell during substanfially the entire balance of the cycle. The suction applied to the suction passages 71 removes the moisture from the slurty to lie filtered Wth the moisture passing through passages 91. vertical bores 51, openings 55 in wear plate 53, thence through suction passages 71 of the main'body of the valve to the outlet 72 which as hereinbefore described is connected to a suitable source of vaccum. Withdrawal of the moisture trom the slurry to be filtered leaves within each of the filter pans a filter cake which is subsequently dumped into hopper 37 When the particular filter pan is inverted through the cooperation of the turn ing lever 78 and the cam 93 as more fully described in my Patent 2,637,443. In the last few degrees of the cycle, the column port is again blanked oi by a solid portion of the valve block just prior to registry of the column port and the blow port and the beginning of a new cycle.

It will be understood that the cycle just describd is merely exemplary and that the several phases of opera' tion may be varied in duration within wide limits by appropriate valve design. Moreover, the blowing phase may be omitted entirely, if desired.

A modified form of the invention is shown in FIGS. 6 and 7 where the novel susbtantially rectilinear flow fea turc is incorporated in the commonly employed two-port rotary filter valve. Referring to FIGS. 6 and 7, 100 designates the pipe plate or rotating port means of the valve which is supported in a suitble trunnion provided with bearing surface means 112 betWen the stationary and rotating parts thereof. The rotating pipe plate 100 is provided with a plurality'of bores .114 which are connected to the filter sections of a rotary pan, rotary drum, rotary dise or the like filter. Bolted to the extended end of the pipe plate 100 is a wear plate 116 provided with a plurality cf bores 118 corresponding in number and size to the bores 114 in the pipe plate 100. By bolting the wear plate 116 by bolts 120 to the pipe plate 100, it will be seeri that both of these structures form rotating portions of the novel valve. At the remote end of the wear plate 116 is a two port valve lock 122 provided with outlet.ports 124 and 126, the function of which will be described in'greater detailhereinafter.

The valve block 122 is axially-mounted to the rotating pipe plate 100 by a center bo1t128 having a head portion which is received in recessl32 in the pipe plate 100.

A bore 134 in the wear plate 116 .permits the passage et 136 so that when thewear plate I16is bolted to the pipe plate 100 anextended end portion of the bolt 128 'proj ects outwardly therefrom. The projected end of the bolt r 128 is rotatably mounted in bearing 138 maintained in a recess140 in the valve block* 122. With this arrangenient, it will be seenthat the valve block122 may be maintained in a fixed position relative to the non-movng portion 110 of the trunnion bearing assembly for the valve. Maintenance et the fixed relationship between the trunnion 110 and the valve black 122 is provided by a pl rality of bolts 142 which pass through boresin a fiange or cars 144 seeured about the valve block. 'iThe extended e'nds 146 of the bolts 142 threadedly engage the stationary part 110 of the trnnnon. The 'other ends otthebolts 142 receive springs l48, washer or plate means 150, and a pair of look nuts 152, lhe spring's, lok nuts and plate means in cooperation with each.cif the bolts 142 resiliently urge the valve block 122 into sealing engagement with the wear plate 116 and compensates for wear in the plate 116 during use of the valve.

In order to control the flow of filtrate from various sections et the filter to port means 124 and 126 through one or more of the plural openings 118 in the wear plate 116 and the conduits 114 in the pipe plate 100, the valve block 122 is provided With one or more adjustable bridge pieces 152 and 154 shown in FIG. 7 of the drawings. The bridge pieces 152 and 154 are maintained in a predetermined position Within the valve block by set screws 156 threadedly engaging the valve block and contacting the outer peripheral surface of the bridge pieces as more fully shown in FIGS. 7 and 8 of the drawings. With the two port type of rotary filter valve, one of the ports, for example, port 124 is connected to a source of reduced pressure and the other port 126 is connected to an additional source of reduced pressure which may be less than the reduced pressure connection to port 124 whereoy a strong vacuum is maintained on a predetermined filter section or sections while the moisture content of the filter cake is high and a reduced vacuum may be applied to the same filter section as the drying process continues and open spaces have formed in the substantially dehydrated filter cake. On valves where only one suction port is provided, it is more dlflicult to maintain a high vacuum for the preliminary drying due to the formation of cracks in the partially dehydrated filter cake. Through the use of two vaccum ports this inherent disadvantage in the single port type valve is eliminated.

As will be clearly seen front FIG. 6 of the drawings, the port means 124 and 126, the bores in the wear plate 116 and the corresponding bores 114 in the pipe plate 100, are in substantial alignment during the suction portion of the filtration cycle whereby a high vacuum along with reduction in turbulence and wear in the valve is maintained as more fully described with reference to the form of invention shown in F188. 1 through 5.

While the present invention has been described in detail in reference to a rotary pan filter, it will be evident that the novel valve construction may be used in a horizontal position and that rotary dise filters or a rotary drum 6 filter could be substituted for the pans 27 without departing from the scope of the present invention.

I claim;

1. In a rotary filtering apparatus including a plurality of filter sections, a relatively rotating port means communicating with the filter sections, a stationary valve block in operafive relation to said port means, said stationary valve block being provided With plural openings therethrough communicafing with at least two selected openings in said port means upon rotation of the port means, the plural openings in said valve block being shaped to provide a substantialiy rectilinear fiow path therethrough and to said selected openings in the port means whereby turbulent flow through the valve means is substantially eliminared and adjustable bridge means carried by said valve block for effecting controlled communication between the plural openings in the valve block and selected ports in said relatively rotating port means.

2. In a rotary filtering apparatus including a plurality of filter sections, a relatively rotating port means having arcuately spaced openings therein communicating With the filter sections, a stationary valve block in operative relation to said port means, said stationary valve block having openings extending rectilinearly through the valve block and each of said valve block openings communicating with at least two seleoted arcuately spaced openings in said port means upon rotation of the port means, said valve block openings being shaped to provide a substantially rectilinear flow path through the valve block openings to and through said selected arcuately spaced openings in the port means, and means for maintaining alignment of said valve block with said port means.

References Cited in the file of this patent UNITED STATES PATENTS 1,668,557 Grondal May 8, 1928 1,765,252 Vernay lune 17, 1930 1,878,998 Akins Sept. 27, 1932 1,917,818 Woodworth July 11, 1933 2,352,330 Lee June 27, 1944 2,563,205 Barnebl Aug. 7, 1951 2,637,443 Schwartz May 5, 1953 

